| Message ID | 20191010113937.15962-9-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | cpuidle: psci: Support hierarchical CPU arrangement | expand |
On Thu, Oct 10, 2019 at 01:39:32PM +0200, Ulf Hansson wrote: > The per CPU variable psci_power_state, contains an array of fixed values, > which reflects the corresponding arm,psci-suspend-param parsed from DT, for > each of the available CPU idle states. > > This isn't sufficient when using the hierarchical CPU topology in DT, in > combination with having PSCI OS initiated (OSI) mode enabled. More > precisely, in OSI mode, Linux is responsible of telling the PSCI FW what > idle state the cluster (a group of CPUs) should enter, while in PSCI > Platform Coordinated (PC) mode, each CPU independently votes for an idle > state of the cluster. > > For this reason, introduce a per CPU variable called domain_state and > implement two helper functions to read/write its value. Then let the > domain_state take precedence over the regular selected state, when idling > the CPU in psci_enter_idle_state(). > > This allows subsequent patches that implements support for PM domains for > cpuidle-psci, to write the selected idle state parameter for the cluster > into the domain_state variable. Furthermore, let's share the needed > functions in a header file, to enable the support for PM domains to be > implemented in a separate c-file. > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > drivers/cpuidle/cpuidle-psci.c | 31 ++++++++++++++++++++++++++++--- > drivers/cpuidle/cpuidle-psci.h | 11 +++++++++++ > 2 files changed, 39 insertions(+), 3 deletions(-) > create mode 100644 drivers/cpuidle/cpuidle-psci.h > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > index 5c30f23a8a7b..a16467daf99d 100644 > --- a/drivers/cpuidle/cpuidle-psci.c > +++ b/drivers/cpuidle/cpuidle-psci.c > @@ -20,17 +20,42 @@ > > #include <asm/cpuidle.h> > > +#include "cpuidle-psci.h" > #include "dt_idle_states.h" > > static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state); > +static DEFINE_PER_CPU(u32, domain_state); > + [nit] for me name 'domain_state' is per domain and for one each in the hierarchical topology. But here it's per cpu, just wondering if we can rename it to provide implicit meaning ? > +void psci_set_domain_state(u32 state) > +{ > + __this_cpu_write(domain_state, state); > +} > + > +static inline u32 psci_get_domain_state(void) > +{ > + return __this_cpu_read(domain_state); > +} > + > +static int __psci_enter_idle_state(int idx, u32 state) > +{ > + return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); > +} > > static int psci_enter_idle_state(struct cpuidle_device *dev, > struct cpuidle_driver *drv, int idx) > { > + int ret; > u32 *states = __this_cpu_read(psci_power_state); > - u32 state = idx ? states[idx - 1] : 0; > + u32 state = psci_get_domain_state(); > > - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); > + if (!state && idx) > + state = states[idx - 1]; This can go as mentioned earlier once we have entry for WFI also. > + > + ret = __psci_enter_idle_state(idx, state); > + > + /* Clear the domain state to start fresh when back from idle. */ > + psci_set_domain_state(0); > + return ret; > } > > static struct cpuidle_driver psci_idle_driver __initdata = { > @@ -56,7 +81,7 @@ static const struct of_device_id psci_idle_state_match[] __initconst = { > { }, > }; > > -static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) > +int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) Can this me made part of patch that uses it instead of here ? -- Regards, Sudeep
On Thu, 24 Oct 2019 at 17:42, Sudeep Holla <sudeep.holla@arm.com> wrote: > > On Thu, Oct 10, 2019 at 01:39:32PM +0200, Ulf Hansson wrote: > > The per CPU variable psci_power_state, contains an array of fixed values, > > which reflects the corresponding arm,psci-suspend-param parsed from DT, for > > each of the available CPU idle states. > > > > This isn't sufficient when using the hierarchical CPU topology in DT, in > > combination with having PSCI OS initiated (OSI) mode enabled. More > > precisely, in OSI mode, Linux is responsible of telling the PSCI FW what > > idle state the cluster (a group of CPUs) should enter, while in PSCI > > Platform Coordinated (PC) mode, each CPU independently votes for an idle > > state of the cluster. > > > > For this reason, introduce a per CPU variable called domain_state and > > implement two helper functions to read/write its value. Then let the > > domain_state take precedence over the regular selected state, when idling > > the CPU in psci_enter_idle_state(). > > > > This allows subsequent patches that implements support for PM domains for > > cpuidle-psci, to write the selected idle state parameter for the cluster > > into the domain_state variable. Furthermore, let's share the needed > > functions in a header file, to enable the support for PM domains to be > > implemented in a separate c-file. > > > > Co-developed-by: Lina Iyer <lina.iyer@linaro.org> > > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > > --- > > drivers/cpuidle/cpuidle-psci.c | 31 ++++++++++++++++++++++++++++--- > > drivers/cpuidle/cpuidle-psci.h | 11 +++++++++++ > > 2 files changed, 39 insertions(+), 3 deletions(-) > > create mode 100644 drivers/cpuidle/cpuidle-psci.h > > > > diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c > > index 5c30f23a8a7b..a16467daf99d 100644 > > --- a/drivers/cpuidle/cpuidle-psci.c > > +++ b/drivers/cpuidle/cpuidle-psci.c > > @@ -20,17 +20,42 @@ > > > > #include <asm/cpuidle.h> > > > > +#include "cpuidle-psci.h" > > #include "dt_idle_states.h" > > > > static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state); > > +static DEFINE_PER_CPU(u32, domain_state); > > + > > [nit] for me name 'domain_state' is per domain and for one each in the > hierarchical topology. But here it's per cpu, just wondering if we can > rename it to provide implicit meaning ? Feel free to suggest something. I couldn't find any better. :-) > > > +void psci_set_domain_state(u32 state) > > +{ > > + __this_cpu_write(domain_state, state); > > +} > > + > > +static inline u32 psci_get_domain_state(void) > > +{ > > + return __this_cpu_read(domain_state); > > +} > > + > > +static int __psci_enter_idle_state(int idx, u32 state) > > +{ > > + return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); > > +} > > > > static int psci_enter_idle_state(struct cpuidle_device *dev, > > struct cpuidle_driver *drv, int idx) > > { > > + int ret; > > u32 *states = __this_cpu_read(psci_power_state); > > - u32 state = idx ? states[idx - 1] : 0; > > + u32 state = psci_get_domain_state(); > > > > - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); > > + if (!state && idx) > > + state = states[idx - 1]; > > This can go as mentioned earlier once we have entry for WFI also. > > > + > > + ret = __psci_enter_idle_state(idx, state); > > + > > + /* Clear the domain state to start fresh when back from idle. */ > > + psci_set_domain_state(0); > > + return ret; > > } > > > > static struct cpuidle_driver psci_idle_driver __initdata = { > > @@ -56,7 +81,7 @@ static const struct of_device_id psci_idle_state_match[] __initconst = { > > { }, > > }; > > > > -static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) > > +int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) > > Can this me made part of patch that uses it instead of here ? Sure, just wanted to keep the all the preparations for the PM domains support together. But you have a point, let me move this part to the patch that needs it. Kind regards Uffe
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index 5c30f23a8a7b..a16467daf99d 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -20,17 +20,42 @@ #include <asm/cpuidle.h> +#include "cpuidle-psci.h" #include "dt_idle_states.h" static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state); +static DEFINE_PER_CPU(u32, domain_state); + +void psci_set_domain_state(u32 state) +{ + __this_cpu_write(domain_state, state); +} + +static inline u32 psci_get_domain_state(void) +{ + return __this_cpu_read(domain_state); +} + +static int __psci_enter_idle_state(int idx, u32 state) +{ + return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); +} static int psci_enter_idle_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int idx) { + int ret; u32 *states = __this_cpu_read(psci_power_state); - u32 state = idx ? states[idx - 1] : 0; + u32 state = psci_get_domain_state(); - return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, idx, state); + if (!state && idx) + state = states[idx - 1]; + + ret = __psci_enter_idle_state(idx, state); + + /* Clear the domain state to start fresh when back from idle. */ + psci_set_domain_state(0); + return ret; } static struct cpuidle_driver psci_idle_driver __initdata = { @@ -56,7 +81,7 @@ static const struct of_device_id psci_idle_state_match[] __initconst = { { }, }; -static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) +int __init psci_dt_parse_state_node(struct device_node *np, u32 *state) { int err = of_property_read_u32(np, "arm,psci-suspend-param", state); diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h new file mode 100644 index 000000000000..e593de1784c3 --- /dev/null +++ b/drivers/cpuidle/cpuidle-psci.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __CPUIDLE_PSCI_H +#define __CPUIDLE_PSCI_H + +struct device_node; + +void psci_set_domain_state(u32 state); +int __init psci_dt_parse_state_node(struct device_node *np, u32 *state); + +#endif /* __CPUIDLE_PSCI_H */